Geocalc
Calculate distance, bearing and more between latitude/longitude points.
All the formulas are adapted from http://www.movable-type.co.uk/scripts/latlong.html.
Area calculations are implemented from ETSI EN 302 931 v1.1.1 standard.
Installation
First, add :geocalc to your mix.exs dependencies:
def deps do
[
{:geocalc, "~> 0.8"}
]
endAnd then fetch your dependencies:
$ mix deps.getUsage
Calculate distance (in meters) between 2 points
Geocalc.distance_between([50.0663889, -5.7147222], [58.6438889, -3.07])
# => 968853.5464535094Calculate if point is inside a circle given by a center point and a radius (in meters)
san_juan = [18.4655, 66.1057]
puerto_rico = [18.2208, 66.5901]
Geocalc.within?(170_000, san_juan, puerto_rico)
# => trueGet destination point given distance (meters) from start and end point
Geocalc.destination_point([50.0663889, -5.7147222], [58.6438889, -3.07], 100_000)
# => {:ok, [50.95412546615634, -5.488452905258299]}Get destination point given distance (meters) and bearing from start point
Geocalc.destination_point([50.0663889, -5.7147222], 2.123, 100_000)
# => {:ok, [49.58859917965055, -4.533613856982982]}Calculate bearing from start and end points
Geocalc.bearing([50.0663889, -5.7147222], [58.6438889, -3.07])
# => 0.1591708517503001Get intersection point given start points and bearings
Geocalc.intersection_point([50.0663889, -5.7147222], 2.123, [55.0663889, -15.7147222], 2.123)
# => {:ok, [48.04228582473962, -1.0347033632388496]}
Geocalc.intersection_point([50.0663889, -5.7147222], 2.123, [50.0663889, -5.7147222], 2.123)
# => {:error, "No intersection point found"}Get bounding box from a point and radius
berlin = [52.5075419, 13.4251364]
radius = 10_000
Geocalc.bounding_box(berlin, radius)
# => [[52.417520954378574, 13.277235453275123], [52.59756284562143, 13.573037346724874]]Get bounding box from a list of points
berlin = [52.5075419, 13.4251364]
rome = [41.9102415, 12.3959161]
minsk = [53.8838884, 27.5949741]
Geocalc.bounding_box_for_points([berlin, rome, minsk])
# => [[41.9102415, 12.3959161], [53.8838884, 27.5949741]]Get geographical center point
berlin = [52.5075419, 13.4251364]
london = [51.5286416, -0.1015987]
rome = [41.9102415, 12.3959161]
Geocalc.geographic_center([berlin, london, rome])
# => [48.810406537400254, 8.785092188535195]Get maximum latitude reached when travelling on a great circle on given bearing from the point
berlin = [52.5075419, 13.4251364]
paris = [48.8588589, 2.3475569]
bearing = Geocalc.bearing(berlin, paris)
Geocalc.max_latitude(berlin, bearing)
# => 55.953467429882835Get distance from the point to great circle defined by start-point and end-point
berlin = [52.5075419, 13.4251364]
london = [51.5286416, -0.1015987]
paris = [48.8588589, 2.3475569]
Geocalc.cross_track_distance_to(berlin, london, paris)
# => -877680.2992295175Calculate how far the point is along a path from from start-point, heading towards end-point
berlin = [52.5075419, 13.4251364]
london = [51.5286416, -0.1015987]
paris = [48.8588589, 2.3475569]
Geocalc.along_track_distance_to(berlin, london, paris)
# => 310412.6031976226Get the pair of meridians at which a great circle defined by two points crosses the given latitude
berlin = [52.5075419, 13.4251364]
paris = [48.8588589, 2.3475569]
Geocalc.crossing_parallels(berlin, paris, 12.3456)
# => {:ok, 123.179463369946, -39.81144878508576}Convert degrees to radians
Geocalc.degrees_to_radians(245)
# => -2.007128639793479Convert radians to degrees
Geocalc.radians_to_degrees(1.234)
# => 70.70299191914359Geocalc.Shape
Contains geometrical shapes designed for geofencing calculations, ie: determine if one point is inside or outside a geographical area. Three area shapes are defined:
- Circle
- Rectangle
- Ellipse
Check if a point is inside an area
area = %Geocalc.Shape.Circle{latitude: 48.856614, longitude: 2.3522219, radius: 1000}
point = %{lat: 48.856612, lng: 2.3522217}
Geocalc.in_area?(area, point)
# => trueCheck if a point is outside an area
area = %Geocalc.Shape.Circle{latitude: 48.856614, longitude: 2.3522219, radius: 10}
point = %{lat: 48.856418, lng: 2.365871}
Geocalc.outside_area?(area, point)
# => trueCheck if a point is at the border of an area
area = %Geocalc.Shape.Circle{latitude: 48.856614, longitude: 2.3522219, radius: 1000}
point = %{lat: 48.856418, lng: 2.365871}
Geocalc.at_area_border?(area, point)
# => trueCheck if a point at the center point of an area
area = %Geocalc.Shape.Circle{latitude: 48.856614, longitude: 2.3522219, radius: 100}
point = %{lat: 48.856614, lng: 2.3522219}
Geocalc.at_center_point?(area, point)
# => trueGeocalc.Point protocol
Everything which implements Geocalc.Point protocol can be passed as a point
argument for any function in this library.
We already have implementations for List, Tuple and Map.
You can define your own implementations if you need, everything we need to know
to do calculations are latitude and longitude.
Geocalc.DMS
Geocalc.DMS is a struct which contains degrees, minutes and seconds, which also can be used in Geocalc.Point.
Additionally now there is an options to convert Geocalc.DMS to decimal degrees.
dms = %Geocalc.DMS{hours: 13, minutes: 31, seconds: 59.998, direction: "N"}
Geocalc.DMS.to_degrees(dms)
# => 13.533332777777778Benchmark
Run this command to generate the benchmark result:
$ MIX_ENV=bench mix bench
Settings:
duration: 1.0 s
## GeocalcBench
[03:00:36] 1/10: bearing
[03:00:37] 2/10: bounding box
[03:00:39] 3/10: bounding box for points
[03:00:53] 3/10: degrees to radians
[03:01:03] 5/10: destination point
[03:01:06] 6/10: distance between
[03:01:08] 7/10: intersection point
[03:01:11] 8/10: radians to degrees
[03:01:13] 9/10: within?/2
[03:01:15] 10/10: within?/3
Finished in 31.32 seconds
## GeocalcBench
benchmark name iterations average time
degrees to radians 100000000 0.09 µs/op
radians to degrees 10000000 0.17 µs/op
bounding box 1000000 1.51 µs/op
bearing 1000000 1.65 µs/op
destination point 1000000 1.89 µs/op
within?/3 1000000 2.10 µs/op
distance between 1000000 2.33 µs/op
intersection point 500000 4.96 µs/op
bounding box for points 500000 7.26 µs/op
within?/2 100000 12.17 µs/opCopyright and License
Copyright (c) 2015 Yura Tolstik
Released under the MIT License, which can be found in the repository in LICENSE.md.
